The invention relates to a spacer for insulating glass panes, comprising a profile body made using a first plastics material, having a main body with a substantially U-shaped cross section with first and second side walls arranged in parallel and an inner wall extending between the first and the second side wall. The spacer further comprises a vapor diffusion barrier extending from a free end of the first side wall to a free end of the second side wall. Further, the vapor diffusion barrier is arranged substantially in parallel to and spaced apart from the inner wall.
Spacers for insulating glass panes of the kind described hereinabove are disclosed in the prior art, for example in EP 1 889 995 A1 and in DE 10 2012 105 960 A1.
Such spacers known in the prior art are frequently used in place of the previously commonly used spacers made of metal for improving the thermal insulation of insulating glass planes in windows, doors, facade elements, and the like, in order to hold two or more glass panes, which form the insulating glass pane, in parallel position to each other.
Spacers processed to a frame, together with the glass panes in the assembled state of the insulating glass pane, form an interspace between the panes.
The glass panes are typically bonded to the spacer using a sealant. The interspace between the panes is sealed by bonding the spacer and the glass panes with a sealant adhering to the spacer and to the glass panes. As disclosed, for example, in DE 198 07 454 A1, sealants such as butyl adhesive, polysulfide, polyurethane, and silicone materials are used.
It is important for spacers for insulating glass panes that they have a high heat transfer resistance, such that an insulation that is as good as possible may be ensured.
Furthermore, it is of importance to configure the spacer in such a way that as little water vapor as possible is able to penetrate into the interspace between the panes from the outside, so that condensation effects may be avoided in the case of a large difference between inner and outer temperatures.
Water and water vapor, respectively, which has penetrated should be removed from the interspace between the panes. For this purpose, a cavity formed by the spacer is often filled with desiccant. The capacity of the desiccant is limited, however, such that the interspace between the panes being closed off also by the spacer in a gastight, in particular moisture-tight, manner is of vital importance.
Here it is of importance to configure the spacer such that also the vapor diffusion barrier seals the interspace in between the panes in a water vapor-tight manner, but that its contribution to the heat conduction is nonetheless kept as small as possible.
Vapor diffusion barriers made of metal (cf. DE 93 03 795 U1) are often used in common spacers made of plastic. Full-metal films made, i.e., of aluminum or steel have a pronouncedly good heat conductivity of about 200 and 50 W/(K·m), respectively, and thereby reduce the heat transfer resistance of the spacer overall.
The object of the present invention is to propose a spacer that accounts for the aforementioned problems to the greatest possible extent and, moreover, that may be produced economically.